A strange grizzled old man appeared at the garden fence.

The word ‘and’ can be used between ‘strange’ and ‘grizzled’ identifying it is a coordinate adjective and a comma should be placed, but not between ‘grizzled’ and ‘old’ meaning that it is a hierarchical adjective and no comma should be used.

Note the addition of a comma to denote the coordinate adjective:

A strange, grizzled old man appeared at the garden fence.